1. Field of the Invention
The present invention relates to a substrate processing apparatus and a substrate processing method for subjecting substrates to processing.
2. Description of the Background Art
Substrate processing apparatuses are used to subject various types of substrates such as semiconductor substrates, substrates for liquid crystal devices, plasma displays, optical disks, magnetic disks, and magneto-optical disks, photomasks, and other substrates to various types of processing.
Such a substrate processing apparatus generally subjects a single substrate to a plurality of different types of processing successively. A substrate processing apparatus as described in JP 2003-324139 A includes an indexer block, an anti-reflection film processing block, a resist film processing block, a development processing block, and an interface block. An exposure device is arranged adjacent to the interface block as an external device separate from the substrate processing apparatus.
In the above-mentioned substrate processing apparatus, a substrate carried thereinto from the indexer block is transported to the exposure device through the interface block after being subjected to anti-reflection film formation and resist film coating processing in the anti-reflection film processing block and the resist film processing block. After the resist film on the substrate is subjected to exposure processing in the exposure device, the substrate is transported to the development processing block through the interface block. After the resist film on the substrate is subjected to development processing to form a resist pattern thereon in the development processing block, the substrate is transported to the indexer block.
With recent increases in density and integration of devices, making finer resist patterns has become an important problem. Therefore, as projection exposure methods allowing for finer exposure patterns, a liquid immersion method has been suggested (see, e.g., WO99/49504 pamphlet). In the projection exposure device according to the WO99/49504 pamphlet, an area between a projection optical system (exposure lens) and a substrate is filled with a liquid, resulting in a shorter wavelength of exposure light on a top surface of the substrate. This allows for a finer exposure pattern.
When exposure processing is performed using the liquid immersion method, if the liquid supplied onto the substrate directly comes into contact with a resist film, a component of the resist film is eluted in the liquid. Thus, the exposure lens is contaminated, resulting in processing defects occurring in the substrate. Furthermore, if the exposure lens is damaged, an excessive cost is required to restore the exposure lens. Therefore, it has been proposed that a resist cover film is formed to cover the resist film (see, e.g., JP 2006-140283 A).
Before the substrate is conveyed to an exposure device, however, a portion of the resist cover film may be stripped from the substrate. In this case, during exposure processing in the exposure device, a component of the resist film or the like is eluted from the stripped portion of the resist cover film, causing the exposure lens to be contaminated.
A portion of the resist cover film may be stripped from the substrate within the exposure device. In this case, the component of the resist film or the like is also eluted from the stripped portion of the resist cover film, causing the exposure lens to be contaminated.